The present invention is directed to a screen sleeve used in combination with a hardenable mass for securing anchoring elements in a receiving material where the sleeve is formed of a wire mesh in the shape of an axially elongated tubular member closed at its leading end and with an outwardly projecting flange extending radially outwardly from the open trailing end of the tubular member.
For fixing anchoring elements in a base material including hollow chambers, such as masonry, screen sleeves are inserted into previously formed openings in the base material and a hardenable mass is introduced into the sleeves under pressure. Such screen sleeves are intended to limit the quantity of the hardenable mass introduced and also to create a holding effect in the hollow chambers in the base material by means of the mass passing through the openings in the sleeve. After the mass is introduced into the sleeve positioned within an opening in the base material, an anchoring element is inserted into the screen sleeve and the anchoring element may be a threaded rod or a threaded anchor sleeve. The anchoring element is fixed by the hardenable mass in the base material with the interposition of the screen sleeve.
A known screen sleeve constructed of wire mesh includes a tubular member closed at its leading end and open at its trailing end. A flange is formed at the trailing end of the tubular member and projects radially outwardly from the member. The flange serves as a stop to limit the insertion of the screen sleeve into the opening formed in the base material. After the introduction of the hardenable mass, a pressure head, acting opposite to the direction of insertion of a fastening element into the sleeve, acts on the sleeve. As a result, after the removal of the device for injecting the hardenable mass into the screen sleeve, the sleeve is partially pressed out of the opening and prior to setting of the mass during which a positive engagement in the base material takes place. If the screen sleeve is to be installed vertically upwardly, it must be prevented from falling out of the opening due to the force of gravity and this requires cumbersome manipulation. Such disadvantages are overcome in another known screen sleeve composed of a hollow tubular member closed at its leading end and constructed of wire mesh with a plastics material flange attached to the trailing end of the tubular member. To assure a self-acting engagement of the screen sleeve in the opening during installation, a ring-shaped section with a smaller diameter and a conically shaped outer contour tapering in the insertion direction is provided with the flange and overlaps the tubular member in the insertion direction for about 10% of its length. During the insertion of the screen sleeve into the opening in the base material, the ring-shaped section wedges itself into the opening due to its conically shaped outer contour by widening outwardly against the surface at the inlet into the opening. This wedging action prevents the screen sleeve from being pushed or pressed out of the hardenable mass before it sets, while it is still under a pressure held, or from falling out of an upwardly directed opening prior to being fixed by the hardenable mass.
A considerable disadvantage of this known screen sleeve is its considerable production cost. Initially, the tubular member formed of wire mesh has to be fabricated and, subsequently, the separately formed flange of plastics material has to be rigidly secured to the tubular member.